The principal objectives of the proposed work are to utilize chemiluminescent and thermochemical methods in the measurement of biologically and clinically important materials. A rapid, high precision (plus or minus 0.3 percent) direct thermometric titration will be employed to standardize protein purity. Thermochemical methods will be used in a very general approach to enzymatic analysis including both the determination of enzyme activity and substrate concentration. A thermochemical probe similar to an enzyme ion selective electrode will be investigated. Thermometric methods for the precise determination of ion binding to proteins particularly that of protein bound to free calcium in human serum will be developed. A chemiluminescence(CL) method is being developed for analysis of chromium in biological materials, particularly in blood serum. The procedure should be readily adapted to automated analysis. Vitamin B-12 catalyzes the luminol reaction, and CL will be used to develop an assay procedure. The method should be highly sensitive. CL will be used to analyze for mixtures of transition metals after ion-exchange separation, and as a general detector for liquid chromatography. Quenching of CL should make it readily adaptable to determining amines, sulfhydryl and phenolic compounds. CL titrations are being developed for sensitive and precise analyses. The projected precision is plus or minus 0.5 percent at the sub-parts-per million level. Studies on the I sub 2-luminol system will be adapted to determination of protein-bound iodine(PBI). CL will be used as a measuring technique after conventional ashing procedures as well as attempting direct measurement without ashing. A study of the role of trace metals in the catalysis of luminol and other CL systems will be carried out. Enzymes producing H sub 2 O sub 2 will be studied. The luminol system can be adapted to enzymatic reactions involving phosphate, amino acids and glucose.